Grinding  machines



Feb. 21. 1956 J. M. LUERS 2,735,235

GRINDING MACHINES Filed Feb. 5, 1953 6 Sheets-Sheet l 4 INVENTOR. E 5 J 2 M izzem.

Feb. 21, 1956 M. LUERS GRINDING MACHINES 6 Sheets-Sheet 2 Filed Feb. 5, 1953 5 C CV y mw x ml M V. WM m M 0 2 g Feb. 21, 1956 J. M. LUERS GRINDING MACHINES 6 Sheets-Sheet 4 Filed Feb. 5, 1955 5 3 g B m9 K m J R m s ,4 I T \Q G m e A m 7 k8 H w k 1. u FC K m r M v: If I m k: m W FM I! a J \W I Q mm Iv- E; E= q 5 am m ,a i w 5 l1%|| R R @m I. J| l I l I I I I l I I I I IlllL l I l I II Feb. 21. 1956 J. M. LUERS GRINDING MACHINES 6 Sheets-Sheet 5 Filed Feb. 5, 1955 Feb. 21. 1956 J. M. LUERS 2,735,235

GRINDING MACHINES Filed Feb. 5, 1953 6 Sheets-Sheet 6 INVENTOR- -70?! M 110216 K l /a910 United States Patent GRINDING MACHINES John M. Luers, Mount Clemens, Mich.

Application February 5, 1953, Serial No. 335,380

11 Claims. (Cl. 51-100) This invention relates to improvements in grinding machines. It is an object of the invention to provide a grinding machine wherein a reciprocating work table is mounted between two carriages both of which are mounted for movement angularly thereto; to provide templates whereby one or both of the carriages, and thus grinding wheels carried by the latter, may either be moved relative to the table as the latter is reciprocated so that a predetermined form is reproduced by the grinding wheels upon a work piece secured upon the work table, or so that one or both the carriages remain stationary throughout each operative stroke of the table to grind the work piece flat longitudinally throughout its length; moreover novel means actuated by movement of the work table prior to completion of its stroke are provided for coaction with the parts connected to the carriages by which profiling movement is adapted to be imparted to the said carriages for gradually feeding the latter toward the work table.

Another object of the invention is to provide a grinding machine including a novel form of feed mechanism whereby the carriages are adapted to be gradually fed toward the work table.

Having thus briefly stated some of the objects and advantages of the invention I will now describe it with the aid of the accompanying drawings, in which:

Figure 1 is a front view of the grinding machine, and

Figure 2 is a view partly in section taken on the line 2-2 of Figure 1.

Figure 3 is an enlarged section on the line 3-3 of Figure 1, and

Figure 4 is a section on the line 4-4 of Figure 3.

Figure 5 is an enlarged view taken on the line 5-5 of Figure 2.

Figure 6 is an enlarged front view showing part of the machine.

Figure 7 is an enlarged section on the line 7-7 of Figure 1.

Figure 8 is an enlarged section on the line 8-8 of Figure 6.

Figure 9 is an enlarged section on the line 9-9 of Figure 7.

Figure 10 is a section on the line 10-10 of Figure 5.

Figure 11 is a section on the line 11-11 of Figure 5.

Figure 12 is a section on the line 12-12 of Figure 9.

Figures 13 and 14 are enlarged sections on the lines 13-13 and 14-14 respectively of Figure 11.

Figure 15 is an enlarged section on the line 15-15 of Figure 6.

Figure 16 is an enlarged section on the line 16-16 of Figure 2.

Figure 17 is an enlarged section on the line 17-17 of Figure 8.

Figure 18 is a section on the line 18-18 of Fig ure 17.

Figure 19 is an enlarged section on the line 19-19 of Figure 7. P

Figure 20 is a detail showing the rack being moved forward by the pawl and dog, and

Figure 21 is a detail showing the position of the pawl and dog during their rearward movement over the rack.

Referring to the drawings, 1 designates a bed of a machine across which a guide 2 is secured centrally of its width. Mounted for reciprocation on the guide 2 is a work table 3 having suitable T-slots 4 therein (Figure 12). Secured to and projecting forwardly from one side of the table 3 is an arm 5 to which a vertically arranged Scotch yoke 6 (Figure 5) is fixedly secured. Mounted on one side of the bed 1 is a motor 7 the shaft 8 of which is disposed at right angles to the path of movement of the table 3. Interposed between the motor shaft 8 and a drive shaft 9 is a conventional clutch mechanism 10, and secured around the shaft 9 is a handwheel 9a for manual rotation of the said drive shaft. Secured to the extremity of the shaft 9 remote from the clutch mechanism 10 is a crank arm 11 having a T-slot 12 (Figures 6 and 15) formed longitudinally in its outer face. Supported in the T-slot 12 is a tubular bolt 13 having a member 14 thereon a projection 15 on which engages the said T-slot and is secured therein by a nut 16 thereby holding, the bolt securely in position. Secured around the outer extremity of the bolt 13 is another nut 17. Extending; into the tubular bolt 13 from its outer extremity is av stem 18 having an integral block 19 thereon which isspaced from the outer face of the nut 17 by a resilient. washer 20. Formed in the outer face of the block 19' is a substantially hemispherical cavity 21 to receive a. ball 22 the opposite side of which is mounted in a recess. 23 of substantially semi-circular cross section formed longitudinally in the outer face of the Scotch yoke 6. Thus as the shaft 9 is rotated, either manually through the handwheel 9a or by operation of the motor 7, the table 5 is reciprocated. A scale 24 is provided upon the crank arm 11 with one extremity in alignment with the axis of the shaft 9 to facilitate the setting of the bolt 13 so that the correct length of stroke may be imparted to the table 3.

Mounted on the bed 1 and spaced from each side of the table 3 are two parallel bearing housings 25 having conventional sealed bearings 26 therein. While the bearings 26 are diagrammatically illustrated in Figure 4, such bearings are of the traveling ball-bearing type as are fully disclosed in the Traveling Ball Bearing Catalog of Thomson Industries, Inc., of Manhasset, New York. The bearing housings 25 are disposed at right angles to the path of movement of the table 3 and each housing on one side of the table is in axial alignment with one of the housings on the opposite side thereof. Mounted for axial movement in the bearings 26 in each housing 25 and projecting outwardly beyond both extremities of the latter is a slide rod 27, and mounted for movement with and carried by the two rods on each side of the table is a carriage 28. Since the construction of each carriage 28 and the arrangement of the various parts thereon is identical I will merely describe one carriage and the parts thereon.

Formed through the carriage 28 parallel with the slide rods 27, usually at a somewhat higher elevation than the latter, and preferably centrally between the said rods is a bearing 29 (Figure 11) which extends from the inner face of the carriage for the major portion of its length. Extending outwardly from the base of the bearing 29 and coaxial therewith is a passage 30 which extends through the outer side of the carriage. Mounted for axial movement in the bearing 29 and projecting inwardly there.- from toward the table 3 is a rod 31 which will act as a follower as hereinafter explained and is tubular as shown at 32 from its outer extremity for a portion of its length and is internally threaded. Extending through the passage is a spindle 33 threaded at its inner extremity to coact with the thread 32 in the tubular portion of the rod 31. Fixed around the spindle 33 intermediately of its length isja collar .34 which bears against thebase of the hearing 29 to hold the spindle against axial movement in one direction. Secured upon the spindle outwardly of the carriage 28 is a handwheel 35 the inner face or which is rotatable against the outer face of the carriage thereby holding .the spindle against axial movement in the other direction, so that upon rotation of the spindle 33 the rod 31 is moved axially relative to the carriage, since means hereinafter described prevent rotation of the said rod '31.

I Mounted for rotation in a secondhorizontalbearing.36 spaced above thebearing 29 andformed parallel with the latter through the carriage 28 .is a trunnion 37 which projects beyond both extremities of the said carriage. Secured upon the inner extremity of the trunnion so that it .is rotatable against the adjacent face of the bearing 36 is a guide 38, and securedaround the outer extremity of the said trunnion is a handwheel 3? the inner face of which is rotatable against the outer face of the said hearing. 36a denotes a lock screw for securing the trunnion and carriage at the desired inclination. Provided on the outer face of the bearing 36 is an indicating mark 40 to register with graduations 41 formed on the handwheel 39 so that the guide 38 may be inclined at any desired angle to the table 3. Mounted for movement along ways formed longitudinally along the inner face of the guide 38 is a slide 42 which is moved by a screw 43 supported for rotation by a bracket 44 secured to one end of the guide 3.8 and having an operating crank 4 5 thereon. The screw 43 coacts Wtih a nut 46 carried by the slide 42. Secured upon the latter is an electric motor 47 mounted upon the spindle 48 of which is a grinding wheel 49. Thus upon operation of the motor 47 work (not shown) secured upon the table 3 may be ground by the wheel 49. Obviously the wheel may be set at different inclinations to the Work by rotary adjustment of the trunnion 37 in the bearing 36, and the slide 42 may be set at any desired position along the guide 38.

Formed longitudinally in the work table (Figure 9) from the front thereof is a bearing 51 in which a spindle 52 is mounted for axial movement. Formed in the periphery of the spindle are longitudinal grooves 53 and 54 of substantially semi-circular cross section. Provided also in the table from the front thereof is an opening 55 parallel with the bearing 51 and threaded from its front extremity to receive a pin 56 the front end of which projects beyond the front of the table and is provided with a suitable handle 57 for turning it. Formed around the rear peripheral portion of the pin 56 is a camming face 58. Extending through the table 3 from one side thereof, and at right angles to the axes of. the opening 55 andthe bearing 51, is a passage 59 which extends across the said openingand terminates in the said hearing. The outer extremity of the passage is plugged as shown at 59a and mounted therein between the camming face 58 and the groove 53 in the spindle 52 are a plurality of balls 60 arranged in line. The ball at one extremity rests partly in the groove 53 and the ball at the opposite extremity rests contiguous to the camming face 58 so that when the pin 56 is secured inwardly the balls are forced toward the spindle 52 to hold the latter immovable, or the distance between the operating portion of the camming face and the groove may be increased to release vthe spindle 52 and permit its free axial movement by turning the pin 56 in the opposite direction.

Mounted on .a stand 61 secured upon the bed 1 toward the front thereof to the left in Figure 8 and substantially centrally of its width is a guide member 62 having a p e aperture me h t th rgh the als whi h. i P r e h he P th 9 znp em rt t e ta e 3- Threadedthrough the aperture 63 is a.screw..64haviuge nut 65 on its rear extremity to prevent its detachment from the guide member 62. Extending laterally'through the guide member (as shown in Figure 17) and terminating in the aperture 63 is a tapped opening 620 having a locking screw 64a in engagement therewith which is adatped to hold the screw 64 against accidental rotation. Formed across the upper face of the guide member 62 above and parallel with the aperture 63 is a slot 66 upon the base of which a rack 67 is mounted for longitudinal movement (Figure 17). The width of the upper portion of the slot 66 is increased as shown at 66a to provide ways,

spaced above the rack 67, in which a strip 68 is mounted for longitudinal adjustment. Formed vertically in each side of the upper face of the guide member 62 outwardly of the slot 66 is a tapped opening 69 to receive a screw F9 around which washers 71 are arranged. These Washers extend over the longitudinal margins of the strip 68 to hold the latter immovable when .thescrews 70 are tightened, and when the screws are loosened thestrip maybe longitudinally adjusted so that its frent extremity liesthe required distance behind the front of the rack for the latter to be fed the desired distance forward by means hereinafter described upon each forward stroke of the work table 3. The front extremity of the rack 671s secured, as by screws 72 in a recess formed across the upper face of the feed member 74. Projecting from opposite sides of the member 74 at right angles to the path of movement of the work table 3 are extension arms 75. The member 74 is also apertured .for the free. passage of the screw 64 therethrough, and secured on the front extremity of the said screw is a knob 640 which is circularly calibrated at 64b (FigureZ). The inner face of the knob forms a stop to limit the forward movement (that is movement to the left in Figure 8) of the mem: ber 74 and the rack 67, sothat by precise adjustment of the screw 64 the forward limit of travel of the member 74, and thus the feed imparted to the grinding wheels 49 through means hereinafter described, may be .accu-L V rately controlled.

Mounted for axial adjustment on the front extremity of the spindle 52 is ahead-7,6 (Figure 20.). Formed longitudinally in the latter, preferably above the spindle 52, is a tapped opening 77 into which a screw 78 havingalarge circular head is threaded. The screw head lies partly in an arcuate groove 79 formed ,in the periphery of the spindle 52 so that upon rotation of the screwthehead 76 is moved relative to the said spindle. head 76 radial to the spindle 52 is an internally threaded bushing 80 which is held :in position by. a set screw :81 (Figure 9). A set-screw 82 :is 'threadedin the bushing-80 in front of which a helical spring 83 is provided which exerts pressure against a ball 84 and retains the latter firmly in engagement with the groove 54 in the'spindle 52 thereby holding the latter againstrotation. However due to the substantially semi-circular form of the groove 54 it is possible by loosening .the setscrew 82 to obtain some rotary adjustment of the spindle so that a dog .87 hereinafter referred to and carried by the head 76 .inay be set to properly engage the rack 67. I

The head 76 is bifurcated from its front extremity to receive a circular pawl carrier 85 which is mounted for pivotal movement upon a pin -36 which extends transversely through the said head; and threaded laterally through one side of the head 76 is .a set screw 76a which is adapted to be tightened against the adjacent side of the pawl carrier 85 to hold the latter against rotation upon its pin 86 when it,- is desired ,to. hold the .pawl immovable. Projecting radially from the pawl carrier 85 is adog 87 which engages the teeth of the rack 67 to move the latter forward upon forward movement of the worktable Toinsure rotationof the pawl carrier 85 so thatthe dog 87 engages the rack 67 an arm 88 projects radiallyfrern Mimi Mounted in the e epawl carriercaud has ,a-yweight'fl9 secured upon its Formed across the periphery of the pawl carrier 85 are two spaced, parallel recesses 90 and 90a of substantially semi-circular cross section, and secured in these grooves are circular pins 91 and 91a respectively which project outwardly beyond the periphery of the pawl. Formed through the head 76 intermediately of its length is a transverse passage 92, and extending forwardly therefrom centrally through the head 76 and terminating at its front extremity between the bifurcated head portions is an opening 93 having an internally threaded bushing 94 therein which is held in position by a set screw 95. Mounted partly in the front extremity of the bushing 94 is a ball 96 which is forwardly urged against the periphery of the pawl 85 by a spring 97 the rear extremity of which rests against a screw 98 threaded into the rear of the bushing 94. As the head 76 is moved forward with the table 3 the dog 87 at first rides over the strip 68. After the dog passes the front of the strip it drops, by rotation of the pawl 85, into engagement with one of the teeth of the rack 67 and advances the latter. At that time the ball 96 is bearing against one side of the pin 91-as shown in Figure 20. However when the rack strikes the inner face of the stop 64c and reaches its forward limit of travel continued forward movement of the head 76 causes pressure to be exerted in a rearward direction by one of the rack teeth against the dog 87 so that the pawl is turned about its axis until the ball 96 bears against the pin 91a as shown in Figure 21. When the pawl is so positioned the dog 87 is above and clear of the rack 67 and may either continue to travel forwardly thereover or rearwardly during part of the return stroke of the work table 3. After the dog has moved rear wardly a certain distance it strikes the front of the strip 68 by which it is forced to reassume its forwardly and downwardly inclined position shown in Figure 7. The dog 87 is preferably secured in the pawl carrier 85 by a set screw 99 so that it may be readily raised sufiiciently to clear the tops of the teeth of the rack when the table is to be reciprocated and no mechanical feed is to be imparted to the grinding wheels. Though, if desired, the dog may also be left in its operating position in the pawl carrier and the latter held immovable by the set screw 76a after the said pawl has been so rotated on the pin 86 that the dog is positioned above and clear of the rack 67.

Secured upon the bed 1 are guide plates 100 (Figures 11 and 13) having elongated slots 101 formed in their upper faces parallel with the rods 31 and in alignment with the axes of the rods 31 which extend above them. Supported at its lower extremity in each slot 101 is a vertical shaft 102 the upper end of which projects through a vertical opening 103 formed through one of the rods 31 adjacent its inner extremity. As the arrangement of both the shafts 102 and their cooperation with the rods 31 and other coacting parts is identical I will now describe the arrangement of one shaft 102 and the parts actuated thereby and coacting therewith.

Secured in the upper and lower side of the opening 103 in the rod 31 are spaced bearings 104 which support the shaft 102 for rotation, and secured around the said shaft between the bearings 104 is a cam 105. Formed axially in the rod 31 from its inner extremity is a passage 106 which terminates in the opening 103. Mounted for axial movement in the passage 106 and having one extremity bearing against the cam 105 is the shank 107 of a guide 108. Formed in the guide from its extremity remote from the passage 106 and in alignment with the latter is an opening 109 to receive the stem 110 of a block 111 in which a substantially hemi-spherical cavity is formed to receive the ball 112 on which a hardened follower 113 is secured which rides against a template 114 secured to one side of the table 3 as the latter is reciprocated. Incidentially it will be noted that the two templates 114 shown in Figure 11 are of different form,

' because the movement of the two rods 31 is entirely in dependent so far as their actuation by the templates is concerned differently shaped oppposite sides of a workpiece may be ground simultaneously. Each follower 113 is retained in contact with its template 114 in the following manner. Mounted adjacent one end of the table 1 is a bracket 120 (Figure 2) in which a shaft 121 is rotatably supported, and fixed around the shaft is a pinion 122 and a pulley 123. Projecting from and secured to the carriage 28 is a rack 124 which is engaged by the pinion 122, and extending around the pulley 123 and secured at one extremity thereto is a cable 125 having a weight 126 fastened on its opposite extremity. The weight tends to turn the pulley 125 and its shaft 121 so that the carriage 28, through the pinion 123 and rack 124, is moved inwardly and consequently the follower 113 remains at all times in contact with the movable template 114 (Figure 11), or with a stationary template 127, one of which is pivotally mounted on the bed on each side of the work table 3. The templates 114, secured on opposite sides of the table 3 as by bolts, are employed if the faces of the work piece (not shown) to be ground are not parallel throughout their length with the path of movement of the work table. However if the faces of the work piece are parallel with the path of movement of the table then it is preferable to employ the templates 127. The latter are pivoted on the bed 1 for adjustment about horizontal axes and are so positioned that when raised the followers 113 bear against them. Their use eliminates the necessity for making long templates 114 the follower contacting faces of which must be absolutely parallel and they are quite expensive to manufacture, and again the elimination of moving templates makes for greater accuracy. When the templates 127 are being employed the only movement which may be imparted to the carriages 28 is through rotation of the cams which is accomplished in the following manner.

ecured around each shaft 102 is a collar having a radial arm 116 projecting therefrom, and connecting each arm 116 with one of the extension arms 75 is a suitable connection consisting in the present instance of a length of cable 117 extending throughout substantially its entire length through a tube 118, so that as the feed member 74 is moved forward with the rack 67 when the latter is gradually advanced step by step by the dog 87 upon successive forward strokes of the work table 3 and the spindle 52, the shafts 102 and the cams 105 are gradually turned. The distance which the rack 67 and the feed member '74 are advanced depends upon the distance which the rack projects in front of the strip 68. If no feed is to be imparted to the rack 67, then the latter is covered throughout its length by the strip 68. When the cams are in their positions shown in Figure 11 the carriages 28 are farthest from the work table 3, and as the cams turn, upon forward movement of the feed member 74, their rotation results in inward movement of the carriages effected by downward movement of the weights 126, provided of course greater outward movement is not simultaneously imparted to the carriages by the movement imparted to the followers 113. It is of course understood that when two opposite sides of a work piece are being ground simultaneously that one template 114 can be, and often is, in coaction with one of the followers 113 while the other is in contact with its template 127.

While in the foregoing the preferred embodiment of the invention is described and shown, it is understood that alterations and modifications may be made thereto provided the said alterations and modifications fall within the scope of the appended claims.

' What I claim is:

1. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating the table, a carriage slidably mounted on the bed for movement at right angles to the path of movement 7 of the work table, a grinding wheel mounted in said carriage and including means for rotating the latter mounted on the carriage, a template mounted on one side of the work table, support means rigidly connected to said carriage, a follower mounted on said support means so as to extend from said carriage toward said template, means urging the carriage toward the work table whereby the follower is retained in contact with the template, means interposed in the support means for changing the distance which the follower projects from the carriage,

and a feed mechanism responsive to reciprocation of the work table including means for actuating the interposed means whereby upon each stroke of the table the carriage is moved toward said table.

2. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating the table, a carriage slidably mounted on the bed for movement at right angles to the path of movement of the work table, a grinding wheel mounted on said carriage and including means for rotating said wheel mounted on the carriage, a template secured to the work table for movement therewith, support means rigidly connected to said carriage, a follower mounted on said support means so as to extend from said carriage toward said template, means for urging the carriage toward the work table whereby the follower is retained in contact with the template, means interposed in the support means for changing the distance which the follower projects from the carriage, and a feed mechanism responsive to reciprocation of the work table including meansfor actuating the interposed means whereby upon each stroke of the table the carriage is moved toward the latter.

3. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating the table, a carriage slidably mounted on the bed for movement at right angles to the path of movement of the work table, a grinding wheel mounted on said carriage and including means for rotating said wheel mounted on the carriage, a template secured to the bed, support means rigidly connected to said carriage, a follower mounted on said support means so as to extend from said carriage toward said template, means urging the carriage toward the work table whereby the follower is adapted to be held in contact with the template, means interposed in the support means for changing the distance the follower projects from the carriage, and a feed mechanism responsive to reciprocation of the work table including means for actuating the interposed means whereby upon reciprocation of the table the carriage is moved toward the latter.

4. A grinding machine including a bed, a work table mountedfor reciprocation thereon, means for reciprocating the table, a carriage slidably mounted on the bed on each side of the work table for movement at right angles thereto, a grinding wheel mounted on said carriage and including means for rotating the latter mounted on each carriage, a template mounted on each side of the work table, support means rigidly connected to each carriage, a follower mounted on each of said support means so as to extend from each carriage toward said templates, means for urging each carriage toward the work table for retaining one of the followers in contact with one of the templates, means interposed in each projecting means for varying the distance which one of the followers projects from its carriage, and a feed mechanism responsive to reciprocation of the work table including means for actuating both interposed means whereby both carriages are adapted to be moved nearer the work table upon each stroke of the latter.

5. A grinding machine including a bed, a work table work table, support means rigidly connected to said car- '8 riage, a follower mounted on said support means so as to extend from "said carriage toward said template and adapted to move in a plane parallel with the .path of movement of the carriage, means for urging the carriage inwardly toward the the table whereby the follower is retained in contact with the template, a rotary member mounted on the support in contact with the means holding the follower for changing the distance which the follower projects from the carriage, and a feed mechanism responsive to reciprocation of the work table including means for turning the rotary member whereby the carriage is fed toward the table.

6. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating the table, a template on one side of the table, a carriage mounted for movement on the bed at right angles to the path of the movement of the work table, a grinding wheel including means for rotating the wheel mounted on the carriage, a rod projecting from the carriage toward the template, means for adjusting the distance which the rod projects from the carriage, a follower, means supporting the follower mounted on the rod for movement coaxial thereto, a rotary cam mounted on the rod for varying the distance which the support means extends from the rod, and a feed mechanism responsive to reciprocation of the carriage including means for turning the cam whereby the carriage is moved at right angles to the table.

7. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating the table, a carriage having a grinding wheel and means for rotating the latter mounted thereon, guide,

means on the bed on which the carriage is mounted for movement angularly to the path of movement of the work table, a rod coaxial with the path of movement of the carriage mounted for axial adjustment in the latter and projecting therefrom, said rod being tubular from' its outer extremity, bearings in the rod extending at right angles to the axis of the latter, a shaft rotatably supported in the bearings, a stern mounted in the outer extremity of the rod for axial movement, a cam fixed around the shaft in contact with the inner extremity of the stem, a follower on the outer extremity of the stem, a template fastened on one side of the work table, means for urging the carriage toward the work table'and retaining the follower in engagement with said template, and a feed mechanism responsive to movement of the work table including means for turning said shaft.

8. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating the table, a carriage having a grinding wheel and means for rotating the latter mounted thereon, guide means mounted on the bed on which the carriage is mounted for movement at right angles to the path of movement of the work table, a rod coaxial with the path of movement of the carriage mounted for axial adjustment therein and projecting therefrom, said rod being tubular from its outer extremity, hearings in the rod extending at right angles to the axis of the latter, a shaft rotatably supported in the bearings, a stem mounted in the outer extremity of the rodfor axial movement, a cam fixed on the shaft in engagement with the inner extremity of the stem, a follower on the outer extremity of the stem, a template mounted on the bed adjacent one side of the work ta le, means for urging the carriage toward the work table and retaining the follower in contact with the template, and a feed mechanism responsive to movement of the work table including means for turning said shaft.

9. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating thetabie, a movable carriage, a guide mounted on the carriage for rotation about an axis parallel with the path of movement of said carriage, a slide mounted for movement along the guide, an electric motor having a shaft mounted on the slide, a grinding wheel mounted on the shaft, guide means on the bed on which the carriage is mounted for movement angularly to the work table, means for urging the carriage toward the work table, a rod coaxial with the path of movement of the carriage mounted for axial adjustment therein and projecting therefrom, said rod being tubular from its outer extremity, coaxial bearings in the rod extending at right angles to the axis of the rod, a shaft rotatably supported in the bearings, a cam secured around the shaft, a stem extending into the tubular extremity of the rod and resting against said cam, a template supported on the work table, a follower on the outer extremity of the stem resting against said template, and a feed mechanism including means for turning the cam responsive to reciprocation of the work table where by the carriage is adapted to be moved,

10. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating the table, a head, means fixed on the table to which the head is secured, a rack, means on the bed for supporting the rack for movement parallel with the work table, means for limiting the forward movement of the rack, a pawl carrier rotatably mounted on the head and having spaced projections thereon, means on the pawl tending to turn it in one direction, a dog projecting from the pawl adapted to engage the rack and move it forward when the table is advanced, yielding means on the head for engaging either projection and tending to hold the pawl against rotation by said means thereon tending to turn it in one direction, said yielding means engaging one of the projections when the dog is in its rack advancing position and engaging the other projection when the dog is positioned to move freely over the rack, means carried by the rack supporting means for turning the pawl during the rearward movement of the work table in the direction opposite to that in which it is adapted to be rotated by the aforesaid means tending to turn the pawl whereby the dog is returned into position to again engage the rack upon the next forward movement of the work table, a carriage including grinding means mounted thereon mounted for movement on the bed relative to the work table, and

10 means for moving the carriage responsive to movement of the rack.

11. A grinding machine including a bed, a work table mounted for reciprocation thereon, means for reciprocating the table, a spindle mounted for axial adjustment in and projecting forward from the table, a head mounted on the spindle, a rack, means on the bed for supporting the rack for movement parallel with the table, adjustable means for limiting the forward movement of the rack, a pawl carrier rotatably mounted on the head and having circumferentially spaced projections on its periphery, means on the pawl tending to turn it in one direction, a dog projecting from the pawl adapted to engage the rack and move it forward with the table, yielding means on the head for engaging either projection and tending to hold the pawl against rotation by the means tending to turn the latter, said yielding means engaging one of the projections when the dog is in its rack advancing position and engaging the other projection when the dog is positioned to travel freely over the rack, a strip mounted for longitudinal adjustment over the rack on the rack supporting means, the front margin of the strip being adapted to engage the dog during the rearward travel of the work table and return said dog into position to re-engage the rack during the next forward stroke of said table, a carriage including grinding means thereon mounted for movement relative to the work table, and means for moving the carriage responsive to movement of the rack.

References Cited in the file of this patent UNITED STATES PATENTS 910,350 Bastian Jan. 19, 1909 1,051,483 Bryant Jan. 28, 1913 2,304,580 Luers Dec. 8, 1942 2,547,670 Skinner Apr. 3, 1951 FOREIGN PATENTS 882 Great Britain Jan. 12, 1907 

